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Supports: HEVC, MOV, MP4, M4V, MKV
A bare .hevc file is a raw H.265 video bitstream — the unwrapped compressed stream an encoder writes out, with no container and no audio track — and FLV is Adobe's Flash Video format, which has been effectively dead since Flash Player reached end of life. This converter does the job, but two things are worth knowing first: the FLV will be silent (there is no sound inside a .hevc to carry over), and FLV's default codec is generations older than H.265, so the picture gets worse and the file usually grows. The tables below explain both formats so you can decide whether FLV is really what you need.
| Property | Value |
|---|---|
| Full name | High Efficiency Video Coding (H.265) |
| Standard | ITU-T H.265 / ISO/IEC 23008-2 (MPEG-H Part 2), first published 2013 |
| Type | Video codec — defines no audio |
.hevc file |
Raw elementary stream: H.265 NAL units only, no container, no audio, no seek index |
| Compression | Roughly 50% smaller than H.264 at equal quality |
| Audio inside | None — a true .hevc has no soundtrack |
| Best for | High-efficiency masters; the H.265 stream usually lives inside an MP4, MKV, or MOV |
| Property | Value |
|---|---|
| Full name | Flash Video (Adobe) |
| Container | FLV |
| This converter's default codec | FLV1 (Sorenson Spark, an H.263 variant from the early 2000s) |
| Default audio codec | AAC (no effect here — the source is silent) |
| Native browser support | None — modern Chrome, Firefox, Edge, Safari, and Opera dropped Flash |
| Player status | Adobe ended Flash Player support December 31, 2020 and blocked Flash content January 12, 2021 |
| Honest use case | A legacy Flash-era CMS, RTMP server, or pipeline that still demands a .flv |
.hevc file onto the page or click "+ Add Files" to browse. You can queue several raw H.265 streams and process them with the same settings.Because a raw .hevc file is an H.265 video elementary stream and holds no audio. HEVC, defined by ITU-T H.265 / ISO/IEC 23008-2, is a video-only codec, so there is no soundtrack inside the file to convert and any FLV produced from a bare .hevc is silent. The audio you remember almost certainly lived in a container — an .mp4, .mkv, or .mov — that wrapped the H.265 video next to a separate audio track, and that audio was left behind when the file was exported down to a raw stream. If you need the sound, convert that original container instead, for example with MP4 to FLV or MKV to FLV.
A re-encode. FLV does not carry the H.265 codec, so there is no way to keep your original stream and simply put it in a .flv. The converter decodes the H.265 frames and re-encodes them to the FLV codec (FLV1 / Sorenson Spark by default), which means a second lossy pass. No setting recovers detail — the best you can do is keep the "Preset" high so the loss stays small. If you want a container that can actually hold the H.265 codec, HEVC to MP4 keeps the video in H.265 rather than dropping to an older codec; FLV cannot.
By default it uses FLV1, also called Sorenson Spark — an H.263-derived codec from the early 2000s. It is generations behind H.265, which compresses roughly 50% better than even H.264, so matching the same picture in the older FLV codec costs substantially more bits. Expect the .flv to be noticeably larger than the .hevc it came from. To claw back size, lower the "Preset" or set a "Specific file size" — at the cost of some quality — or skip FLV entirely with HEVC to MP4 if you do not specifically need a Flash file.
For almost everyone, no. Adobe ended Flash Player support on December 31, 2020 and began blocking Flash content on January 12, 2021, and modern browsers no longer play Flash natively. The only honest reason to output .flv today is a legacy Flash-era pipeline — an old RTMP streaming server, a content management system, or a player that was built around the format and still expects that extension. If you just want a clip that plays widely and stays efficient, use HEVC to MP4 instead: MP4 wraps the H.265 family properly and plays on phones, browsers, and most software, where FLV needs a player that predates the Flash shutdown.
Probably not. A raw H.265 elementary stream has no container and no seek index, so many media players reject it on open even though the data is fine. The converter reads the stream regardless, so the upload and conversion still work even if your local player cannot preview the source. If you want a .hevc that opens in ordinary players, wrap it in a modern container with HEVC to MP4 or HEVC to MKV rather than dropping to FLV.
In our testing, re-encoding a short raw H.265 stream to the default FLV codec produced a noticeably larger, silent file than the source — the expected cost of a video-only input and an older codec. Your file is uploaded over an encrypted connection, decoded and re-encoded into FLV on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public.
Desktop media players that read the streams directly — VLC, MPC-HC, and PotPlayer among them — still open FLV without Flash. No current web browser does, because Chrome, Firefox, Edge, and Safari all removed Flash around its December 2020 end of life.
That gap is the whole reason to think twice before choosing FLV: unless a specific legacy pipeline demands it, HEVC to MP4 plays far more widely.
No, though both are Adobe Flash video. FLV — what this tool outputs — uses older codecs such as FLV1/Sorenson Spark or VP6 in Adobe's own container. F4V is newer, built on the ISO base media file format (the MP4 family) and carrying H.264 video, so it generally looks better at a smaller size. Both are legacy targets today; pick either one only if a Flash-era player specifically requires that extension.